An air conditioner having a slide door is described in JP-A-8-290714 (corresponding to U.S. Pat. No. 5,701,949) and JP-A-11-20453, for example. FIG. 8 is a perspective view showing a slide door 12A in JP-A-8-290714, and FIG. 9 is a perspective view showing a slide door 12B in JP-A-11-20453. However, in both the slide doors, when one passage opening portion is closed by the slide door 12A or 12B, a sealing may be not completely performed.
FIG. 10A shows an air conditioner using the slide door 12A in FIG. 8 when a maximum hot state is set. During the maximum hot state, a first passage opening portion 42 communicating with a heater core 5 is fully opened, and a second passage opening portion 43 through which air bypasses the heater core 5 is closed. In this state, a link portion 23 for connecting the slide door 12 and a link lever 35 is positioned in the second passage opening portion 43.
Furthermore, in a maximum cold state shown in FIG. 10B, the slide door 12 fully opens the second passage opening portion 43 and fully closes the first passage opening portion 42. In this state, the link portion 23 for connecting the slide door 12 and the link lever 35 passes a partition portion 11 between both the first and second passage opening portions 42, 43, and is moved into the first passage opening portion 42. That is, as shown in FIG. 10C, in order to set both the maximum hot state and the maximum cold state shown in FIGS. 10A and 10B, it is necessary to provide a recess portion K for passing the link portion and a rotation tip portion of the link lever 35.
Accordingly, in the maximum hot state shown in FIG. 10A, the second passage opening portion 43 is not completely closed, and a part of air to pass through the heater core 5 in the first passage opening portion 42 leaks from the first passage opening portion 42 toward the second passage opening portion 43 through the recess portion K in the partition portion 11. Similarly, in the maximum cold state shown in FIG. 10B, the first passage opening portion 42 is not completely closed, and a part of air to pass through the second passage opening portion 43 leaks toward the first passage opening portion 42 on the side of the heater core 5 through the recess portion K of the partition portion 11.
By contrast, in the slide door 12B shown in FIG. 9, an air leakage may be caused through cut portions of guide grooves 33 for rotating link levers 35 on two sides of the slide door 12B, similarly to the recess portion K.